Legislation to block a $30 billion damages claim by businessman Clive Palmer is likely to pass WA Parliament after the Nationals and the Greens decided they would not support a move to send the bill to a committee inquiry.

Attorney-General John Quigley said the state could not afford any delays.

“I want to see the Governor’s signature on this legislation this evening,” Mr Quigley told ABC Radio Perth.

“Once the legislation passes and becomes law, the arbitration is terminated as of last Tuesday, two days ago.

“I’m pleading with all members of the Upper House, all members of the Upper House to move swiftly to protect all Western Australians. This is crucial that this bill is introduced and passed.”

• Why Clive Palmer has the WA government so worried

Mr Palmer and the WA government have been engaged in arbitration over a dispute relating to his iron ore interests in the Pilbara region of WA.

Mr Quigley has told Parliament Mr Palmer is seeking more than $30 billion in damages.

Legislation to block the arbitration and any liability by the state of Western Australia passed the Legislative Assembly on Wednesday night, with the support of the opposition, and was to be debated in the Legislative Council on Thursday.

The opposition wants the bill, which also denies the right to natural justice and to freedom of information requests on this specific matter, to be reviewed by a joint select parliamentary committee.

But that attempt looks set to fail, with the Nationals and Greens confirming they will not support the committee inquiry and any delay.

It leaves a clear pathway for the government to pass its legislation.

Mr Quigley said there was no time for committee review.

“We’ve got to unleash the left hook today. We’ve got to knock him down today. There is too much at risk for all Western Australians for namby-pamby inquiries,” he said.

“This legislation has been crafted over the last six weeks in secret by the best legal minds in this city.”

Attorney-General John Quigley said the state had to move fast to beat Mr Palmer. Photo: AAP

‘What did McGowan do?’: Palmer

In a statement, Mr Palmer questioned why Premier Mark McGowan and his government wanted to prevent citizens and the media finding out what the state had done to cause it to incur a liability of $30 billion.

“Why was the act passed in the Western Australian Parliament which takes away the rights of the press and the Western Australian public to make FOI applications to find out what McGowan did?” he said.

“The question for Western Australians is what did McGowan do to cause, as the Attorney-General said, $30 billion dollars of liability for the State of Western Australia? Why should McGowan or anyone else be exempt from the criminal law?”

Despite Mr Palmer’s comments, the arbitration matter the bill seeks to quash is a question of civil, not criminal law.

Mr Palmer also asked why there was an emergency to pass the legislation in one day, and whether it was linked to his High Court challenge to Western Australia’s hard border closure.

Mr Quigley said the legislation had been prepared in secret and introduced late on Tuesday for tactical reasons to take advantage of a “weakness” in Mr Palmer’s position.

Tweet from @CliveFPalmer

Legislation timed to outflank Palmer

An arbitrator found in favour of Mr Palmer’s company Mineralogy in 2014 over the iron ore dispute, but in the following six years had failed to register the award in the Supreme Court.

Once the award is registered in court, it is protected by the constitution.

Mr Quigley said the arbitration and the award therefore had to be terminated before Mr Palmer could now register the award, which is why he introduced it to Parliament after every court in the country had closed on Tuesday night.

“It was too late for him to get to a court,” he said.

He said he believed Mr Palmer was trying to register the award in the Supreme Court of NSW.

But if the legislation passes, it will terminate the arbitration and any damages from the time the bill was introduced to Parliament on Tuesday.

“What he’s doing now, too late we think, is trying to register it,” Mr Quigley said.

“Had he got a whisper of what the government was about last week … and made his move to the court then, we would have been in all sorts of difficulty, because once the matter is before the court, the independence of the court is protected by chapter three of the constitution.”

Mr Palmer has targeted WA Premier Mark McGowan as he steps up the fight.

Stonehouse pushes for more scrutiny

Liberal Democrat and crossbencher MP Aaron Stonehouse called for a committee inquiry, saying the bill needed to be scrutinised thoroughly so all its risks were completely understood.

“What I suspect is that the Premier and the Attorney-General are going to stamp their feet,” he said.

“They are going to become shrill, they are going to complain, they’re going to yell and scream, but I think the public deserve to know exactly what’s involved in this bill.

“There are clearly risks that there could be a constitutional challenge, there are financial risks of course to the state. But I think as a Parliament we can take pause, maybe a week, two weeks at the absolute most, to get some independent legal advice.”

Opposition leader Liza Harvey said it was complex and sensitive legislation, and it could benefit from further review.

“It would provide some oversight and perhaps strengthen the bill to ensure there won’t be a High Court challenge,” she said.

“There’s a lot of really talented lawyers in the Upper House who could potentially look at the bill and look at ways to strengthen it.”

Mr Palmer has already threatened a High Court challenge if the extraordinary legislation is passed.